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OPENING - Embedded Linux, Open WRT contract in northern MA
by John Spencer Nov. 6, 2013

Nov. 6, 2013

We have a client in northern MA looking for a Sr or Prin level consultant for a new project They are looking for experience with embedded Linux and OpenWRT. If you or anyone you know may be qualified and interested, please let me know. I would be happy to share additional details. Please send a Word version of your resume with any questions. Please Note, your resume will not be sent anywhere without your prior approval. Regards, John Spencer Connected Systems Partners Connecting Top Talent with Top Companies 978-455-5550 x208 978-621-9743 cell jspencer(a)connectedsp.com www.connectedsp.com<www.connectedsp.com%20> GET CONNECTED! Unless otherwise explicitly instructed by sender, all information in this email is considered confidential and intended for the view and use of the recipient(s) only.

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Announce: WLUG Meeting Wed 11/13 7PM: OpenWRT
by Chuck Anderson Nov. 6, 2013

Nov. 6, 2013

Hi folks, The next Worcester Linux Users' Group (WLUG) meeting will be held NEXT Wednesday, November 13 at 7PM. The location will be the WPI Campus Center, Mid-Centry Room 331. We will have a discussion of people's experiences with OpenWRT, and perhaps a demo of how to load OpenWRT on a Netgear home wireless router and configure it for Bufferbloat avoidance/improvement. Wednesday, November 13, 7:00 - 9:00 PM WPI Campus Center, Mid-Centry Room 331 Afterwards, we will go out for pizza. See you there, Chuck President, Worcester Linux Users' Group http://www.wlug.org/

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OpenWRT on WNDR3800 home router - my install thoughts
by joel d Nov. 4, 2013

Nov. 4, 2013

Decided to try OpenWRT after Jim Getty's talk and strong recommendation last month for improved security and reduced local buffer bloat. What follows is my experience / thoughts from this process. I would happily bring the hardware to demo at a future meeting if there is interest. Likely wouldn't be a full meeting but a 10-15 minute filler. More likely Q&A than anything else. I decided to go with different router/firewall hardware so I bought a Netgear WNDR3800 which Jim mentioned and is also a favorite of the OpenWRT crowd. Mine was used and $50 shipped from e-bay. This model is one model old and no longer available new. FYI: Netgear website lists it as "out of support". My WNDR3800 was used prior, so I needed to do a hard firmware reset on the bottom of router with a paperclip (didn't know the prior IP used or the admin password). Once reset and rebooted, router worked fine and could login to the "default" Netgear firmware and configuration. Default username & password is printed under the router. Downloaded the recommended OpenWRT firmware for this model. Needs to be full "factory" (instead of partial upgrade) and squashfs is recommended. Netgear WNDR3800 Firmware download link gets you OpenWRT version 10.X version which is not latest OpenWRT. Web browser login to Netgear webpage/firmware and followed "upgrade firmware" link while pointing to OpenWRT download file on local disk. The upgrade/re-flash took around 4 minutes and after a reboot worked fine. Set password and reconfigured router and WIFI with my specifics. Was up and working on OpenWRT v 10.x. Next day realized I had OpenWRT, but not latest stable version. Upgrade firmware link does not go to Internet directly, so first download OpenWRT v 12.4 with "upgrade" and "squashfs" and save to local disk. Second apply this via upgrade button in OpenWRT web link. I could likely have saved a step by grabbing the OpenWRT v12.4 for WNDR3800 with factory and squashfs. I bet this would have worked had I tried it (and saved a step). General thoughts after use for a week: OpenWRT does not have an "update direct to mother ship" feature best I can tell that downloads file and updates it from web interface. Not a show stopper for me. Instead need to know your version of OpenWRT and download an "upgrade" file and apply as two steps. This would only matter if router was used/maintained by a non-geek. Prior problem occurred with similar hardware WNDR3700 with latest Netgear firmware (happened with prior Linksys also). A few embedded WIFI devices in home would disconnect and fail randomly and at least weekly. Thus far these device annoyances have not occured since swap to WNDR3800 and OpenWRT. No idea why, but definitely A win! OpenWRT has transmit power level settings for the WIFI radio transmit. Can decide to bump up the WIFI radio settings if user chooses. Even if you melt/destroy them, a cool option if needed & tested. Firmware update for OpenWRT works from a laptop on WIFI, which in my experience Netgear & Linksys and other vendors do not support flash without a cabled ethernet port. So the OpenWRT update scripts the 1) copy file 2) apply file 3) reboot device. My Next Steps: In another week will likely repurpose the WNDR3700 likely as a WIFI gateway for the "cheap WIFI radio" devices, (mainly TV, roku, DVD, etc.). Not yet sure if I will use OpenWRT for this. Look into the option of external antennas for the WNDR3800. I live out in the country and have few neighbors to notice/know/care. If I can get there... improved & reliable WIFI signal at my mailbox would rock.

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Idiot Service Providers
by Keith Wright Oct. 23, 2013

Oct. 23, 2013

On recomendation from someone on this list, I signed up for Speakeasy DSL. The helped me set up a primary name server (DNS) and they ran a secondary name server for a few extra dollars per month. This has been working well for about a decade. Speakeasy was sold to MegaPath, who yesterday sent me a message that included this: > Dear MegaPath Customer, > > This email is to advise you that MegaPath is > migrating its legacy Speakeasy ISP, web hosting, > webmail and DNS services to a more advanced platform. > > <Braindead "customer-experience" > happy market-talk deleted> > > Going forward, we will no longer support secondary > DNS services. If your domain is set up in this > manner, please be sure to make the proper changes to > avoid a post-migration service disruption. This all happens next Tuesday. I read this is "We are breaking what has worked for a decade, there is nothing you can do, have fun finding a new ISP in two days." I was wall-punching cursing mad. When I calmed down a bit I began to think, if they don't break anything else, maybe it's not so bad. The system was designed to tolerate failure. _I_ was not designed to tolerate _intentional_ failure, but everything should still work if the secondary name server is broken. Since I have only one IP address on one DSL line, I never really saw the need for a secondary server in the first place. I run a primary server because (A) I like to think of myself as a programmer, and it is self education to figure out how to do it. (B) Sometimes I create subdomains and run test program servers in them. The RFC's require a second name server, and the registrar asks for it, but who's going to care really? If the primary name server goes out, so do all other servers in the domain, since it's all really just one computer. What would you recommend? If anyone else has the same problem, I could be your secondary, and you could be mine. -- Keith

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Barbarians at the gates...
by Tim Keller Oct. 21, 2013

Oct. 21, 2013

This is a paper about High Frequency Trading, it's an interesting if not entirely terrifying read about what a crazy place the markets have become. http://queue.acm.org/detail.cfm?id=2536492 Tim. -- I am leery of the allegiances of any politician who refers to their constituents as "consumers".

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Bufferbloat demonstrations w/water and funnels
by Chuck Anderson Oct. 14, 2013

Oct. 14, 2013

Here is a series of videos of a talk by Dave Täht where he uses water and funnels to demonstrate the concepts of bufferbloat: [1] Bufferbloat #1 - TCP 101 [2] Bufferbloat #2 - Tail drop queueing [3] Bufferbloat #3 - FIFO, RED, Blue, and Fair Queueing [4] Bufferbloat #4 - Wifi, Netalyzr, SFQ, SFQRED, and CoDel [5] Bufferbloat #5 - CoDel and Drop Head Queueing [6] Bufferbloat #6 - More on FQ_Codel [7] Bufferbloat #7 - Q&A [1] http://www.youtube.com/watch?v=KD5TwLQnq_8 [2] http://www.youtube.com/watch?v=PgFcqRMDqlk [3] http://www.youtube.com/watch?v=Y9xJbwb28Zc [4] http://www.youtube.com/watch?v=ol_BcKA9Ohg [5] http://www.youtube.com/watch?v=R8Esi0zjNdE [6] http://www.youtube.com/watch?v=bi-jumVNVGk [7] http://www.youtube.com/watch?v=JFH5fGNzBJU

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Changing your network scheduler in ubuntu 13.04...
by Tim Keller Oct. 14, 2013

Oct. 14, 2013

Just so people know... this is how to change the scheduler on Ubuntu 13.04. tc qdisc replace dev eth0 root fq_codel limit 100 target 5ms interval 30ms ecn Obviously replace "eth0" with your appropriate network device... Enjoy, Tim. -- I am leery of the allegiances of any politician who refers to their constituents as "consumers".

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Reminder: WLUG Meeting Wed 10/9 7PM Jim Gettys on Internet buffer bloat
by Chuck Anderson Oct. 7, 2013

Oct. 7, 2013

Hi folks, The next Worcester Linux Users' Group (WLUG) meeting will be held this Wednesday. This month we will have Jim Gettys from Bell Labs talk about Internet buffer bloat. This is the talk that has been rescheduled from April. Note that there has been a room change to a larger room right down the hall from our regular location. Wednesday, October 9, 7:00 - 9:00 PM WPI Campus Center, Hagglund Room 301 The Campus Center is building #7 on the campus map [1], and the Hagglund Room is room 301 on the Campus Center building floorplan [2]. [1] http://www.wpi.edu/about/visitors/campusmap.html [2] http://www.wpi.edu/Admin/CC/Floorplans/37678.htm "Internet buffer bloat, by Jim Gettys (Bell Labs) VOIP and teleconferencing often perform much more poorly on today's Internet than the Internet of a decade ago, despite great gains in bandwidth. Lots of fiber, cheap memory, smart hardware, variability of wireless goodput, changes in web browser behaviour, changes in TCP implementations, and a focus on benchmarking Internet performance solely by bandwidth, and engineer's natural reluctance to drop packets have conspired to encourage papering over problems by adding buffers; each of which may introduce latency when filled. The mistaken quest to never drop packets has destroyed interactivity under load, and often results in actual higher packet loss, as TCP's congestion avoidance algorithms have been defeated by these buffers. The lessons of the "RED manifesto" of 1997 have been forgotten or never learned by a new generation of engineers." Wednesday, October 9, 7:00 - 9:00 PM WPI Campus Center, Hagglund Room 301 Afterwards, we will go out for pizza. See you there, Chuck President, Worcester Linux Users' Group http://www.wlug.org/

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Announce: WLUG Meeting Wed 10/9 7PM Jim Gettys on Internet buffer bloat
by joel d Oct. 3, 2013

Oct. 3, 2013

I plan to attend Wednesday's meeting also (90% likely at this point). Joel

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Announce: WLUG Meeting Wed 10/9 7PM Jim Gettys on Internet buffer bloat
by Chuck Anderson Oct. 3, 2013

Oct. 3, 2013

Hi folks, The next Worcester Linux Users' Group (WLUG) meeting will be held at its regularly scheduled time: the 2nd Wednesday of the month, which is Wednesday, October 9, at 7PM. The location will be the WPI Campus Center, Mid-Centry Room 331. This month we will have Jim Gettys from Bell Labs talk about Internet buffer bloat. This is the talk that has been rescheduled from April. "Internet buffer bloat, by Jim Gettys (Bell Labs) VOIP and teleconferencing often perform much more poorly on today's Internet than the Internet of a decade ago, despite great gains in bandwidth. Lots of fiber, cheap memory, smart hardware, variability of wireless goodput, changes in web browser behaviour, changes in TCP implementations, and a focus on benchmarking Internet performance solely by bandwidth, and engineer's natural reluctance to drop packets have conspired to encourage papering over problems by adding buffers; each of which may introduce latency when filled. The mistaken quest to never drop packets has destroyed interactivity under load, and often results in actual higher packet loss, as TCP's congestion avoidance algorithms have been defeated by these buffers. The lessons of the "RED manifesto" of 1997 have been forgotten or never learned by a new generation of engineers." Wednesday, October 9, 7:00 - 9:00 PM WPI Campus Center, Mid-Centry Room 331 Afterwards, we will go out for pizza. See you there, Chuck President, Worcester Linux Users' Group http://www.wlug.org/

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